Diesel exhaust fluid, or DEF, is a key component in lowering pollutants emitted from diesel engines, helping to improve efficiency and reduce emissions.

In this article we will look at how this system works, what it does, how it breaks and, lastly, what to do if/when it fails.

When DEF runs out or a system sensor fails, current systems can force a vehicle to drastically reduce speed or become ...

Rislone's DEF Crystal Clean dissolves crystalized urea so your DEF system works as it should.

“We have heard loud and clear from small businesses across the United States that the current DEF system is unacceptable," EPA Administrator Lee Zeldin said.

The Environmental Protection Agency (EPA) announced a revision to diesel exhaust fluid (DEF) guidelines to prevent diesel on-road trucks and off-road equipment from severe power loss after running out ...

The EPA on Tuesday said new trucks won't derate due to DEF system faults nearly as quickly or severely, and announced plans to modify software on all existing trucks to extend the timing for derates.